UBS Chief Executive Officer Sergio Ermotti said the world’s wealthiest are staying on the sidelines when it comes to crypto-currencies.

“People are more curious than really willing to invest,” Ermotti said in a Bloomberg Television interview in New York on Tuesday. “I don’t think there’s any meaningful desire by high net worth individuals to take big bets on this kind of phenomenon.”

Bitcoin has surged more than 300 percent this year, drawing the attention of hedge funds and wealthy individuals. China cracked down on crypto-currency exchanges in September, while the SEC said in July that sales of some new digital currencies would be subject to rules just as equities are.

“We believe existing currencies may move into becoming more of a crypto-currency,” Ermotti said. “We don’t really believe there’s much room for the creation of new currencies if there is no real backing for a hard and credible issuer of that currency.”